fix: add missing Anthropic models type and update the anthropic docs

.changeset/add-anthropic-models-export.md

@@ -0,0 +1,64 @@
+---
+'@tanstack/ai-anthropic': major
+---
+
+## Add missing AnthropicModels type export
+
+### WHAT
+
+Added new `AnthropicModels` **type** export to the public API of `@tanstack/ai-anthropic`. This is a union type that represents all supported Anthropic model identifiers, derived from the internal `ANTHROPIC_MODELS` const tuple.
+
+```typescript
+export type AnthropicModels = (typeof ANTHROPIC_MODELS)[number]
+// Equivalent to: 'claude-opus-4-5' | 'claude-sonnet-4-5' | 'claude-haiku-4-5' | ... (and more)
+```
+
+**Note:** The `ANTHROPIC_MODELS` const tuple itself remains internal and is not exported. Only the derived type is part of the public API.
+
+### WHY
+
+Consumers previously had no easy way to get the type-safe union of model names for use in function signatures and variable declarations.
+
+### HOW - Consumers Should Update
+
+Now you can import and use `AnthropicModels` for proper type safety when creating adapter instances:
+
+```typescript
+import { createAnthropicChat, AnthropicModels } from '@tanstack/ai-anthropic'
+
+const adapter = (model: AnthropicModels) =>
+  createAnthropicChat(model, process.env.ANTHROPIC_API_KEY!, {
+    // ... your config options
+  })
+
+const stream = chat({
+  adapter: adapter('claude-sonnet-4-5'), // Type-checked model selection!
+  messages: [{ role: 'user', content: 'Hello!' }],
+})
+```
+
+The type ensures only valid Anthropic model identifiers can be passed, preventing runtime errors.
+
+### Breaking Change
+
+`createAnthropicChat` now requires the model as the first parameter. If you were calling it without a model parameter, you must update your code:
+
+**Before:**
+
+```typescript
+const adapter = createAnthropicChat(process.env.ANTHROPIC_API_KEY!, {
+  // ... config
+})
+```
+
+**After:**
+
+```typescript
+const adapter = createAnthropicChat(
+  'claude-sonnet-4-5',
+  process.env.ANTHROPIC_API_KEY!,
+  {
+    // ... config
+  },
+)
+```

docs/adapters/anthropic.md

@@ -28,11 +28,12 @@ const stream = chat({
 
 ```typescript
 import { chat } from "@tanstack/ai";
-import { createAnthropicChat } from "@tanstack/ai-anthropic";
+import { createAnthropicChat, AnthropicModels } from "@tanstack/ai-anthropic";
 
-const adapter = createAnthropicChat(process.env.ANTHROPIC_API_KEY!, {
-  // ... your config options
-});
+const adapter = (model: AnthropicModels) =>
+  createAnthropicChat(model, process.env.ANTHROPIC_API_KEY!, {
+    // ... your config options
+  });
 
 const stream = chat({
   adapter: adapter("claude-sonnet-4-5"),
@@ -51,7 +52,7 @@ const config: Omit<AnthropicChatConfig, 'apiKey'> = {
 
 const adapter = createAnthropicChat(process.env.ANTHROPIC_API_KEY!, config);
 ```
- 
+
 
 ## Example: Chat Completion
 

packages/typescript/ai-anthropic/src/index.ts

@@ -27,6 +27,7 @@ export {
 export type {
   AnthropicChatModelProviderOptionsByName,
   AnthropicModelInputModalitiesByName,
+  AnthropicModels,
 } from './model-meta'
 export type {
   AnthropicTextMetadata,

packages/typescript/ai-anthropic/src/model-meta.ts

@@ -372,6 +372,8 @@ export const ANTHROPIC_MODELS = [
   CLAUDE_HAIKU_3.id,
 ] as const
 
+export type AnthropicModels = (typeof ANTHROPIC_MODELS)[number]
+
 // const ANTHROPIC_IMAGE_MODELS = [] as const
 // const ANTHROPIC_EMBEDDING_MODELS = [] as const
 // const ANTHROPIC_AUDIO_MODELS = [] as const